Tension device



AAllg- 15 19,50 L. c. MARsc 2,518,703

TENSION DEVICE Filed Aug. 9, 1946 2 Sheets-Sheet 1 gnbenkoz/ e,eozard Marsa/0 @www "o3 7 7,77 I kLoznaq/ Patented ug. l5, 1950 UNITEDSTATES PATENT OFFICE rThe Singer Manufacturing Company, Elizabeth, N. J., a corporation of New VJersey Application August 9, 19416,` Serial No. 689,430

15 Claims. (C11 242-150) This invention relates to sewing machines and more particularly to an improved thread tension device installed in the bracket-arm head of a family type sewing machine.

Mechanisms for tensioning the needle thread of sewing machines are known in the art.' However, previously Yused' tension devices, that have been generally accepted by the trade, 4have 'been positioned mainly eXteriorly of the sewing'machine head. It is a primary object of the present 'invention Vto provide an improved thread tensioning device, a major portion of which is re- 'ceived within an aperture provided in the head of a family type sewing machine. In other words, it is an object ci the invention to provide a compact tension device that has a minimum protuberance from'the head of the machine.y

Another object of the invention is to provide a generally improved thread tension device for use with sewing machines. e Still another object of the invention is toprovide a "thread tension device having a simple means for accurately adjusting the degree of tension imposed upon the needle thread.

Other important objects of the invention will be apparent from the following detailed description and appended claims.

The invention` consists in the devices, combinations and arrangements'of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understoodby those skilled inthe art.

In the accompanying drawings: f

Fig. 1 is a side elevational view of aportion of a sewing machine bracket-arm tted with a tension device embodying the invention;

' Fig. 2 is'an end elevational View of the bracket- "arm and tension device shown in Fig. 1;

`Fig.v 3 is a sectional view taken on the line 3-3 of Fig. 1 andlooking in the direction ofthe arrows;

Fig. 4 is a top plan View of the tension device, a portion of the bracket-arm being shown'in section;

Fig. 5 is a; sectional view taken substantially on the line 5-5 ofFig. 3 and looking inthe direction of the arrows; and A Fig; 6 is anexploded perspective view of the tension device. f 1 v In the preferred embodiment of the invention illustrated in the drawings, numeral l l rindicates ,an overhanging bracket-arm` of a familyV type sewing machine. VIhearm terminates in a head l2Y that: supports the. usual reciprocating needle bar i3, thread take-up lli, presser-bar l5, and presser-bar lifter Il. A V-shaped tension-releasing lever I8, having arms I9 and 2i, is pivotally supported inthe headlZ by a screw 22. The arm l!) isoperated by the presser-bar lifter I1 when the lifter approaches fully raised position. The arm`2l, which is biased counterclockwise by a beehive spring 2i, is provided with a boss 26, the purpose of which will hereinafter appear.

' The head l2 also supports a tension device 2l', 'a major portion of which is received within an aperture 28 (Figs. 3 and l) formed in the head l2. The rear portion of the tension device is disposed in a cylindrical hole 29 forming a reduced extension of the aperture 28 through the inner wall of the head l2.

The tension device comprises a plate 3| having a cylindrical aperture into which is fitted the 'front end of a support member that is in the formV of a hollow cylindrical or tubular barrel 32. An'annular lip 33 (Fig. 3), on the front end of the barrel 32 is spun over the edge of the hole in the` plate 3l and, thereby, securely holds the plate against'the-front face of a Shoulder 3d formed on the barrel 32. The plate 3l is adjustably held to the head l2 by a screw 36 which passes through a slotted countersunk hole 3l and then enters a threaded hole 38 in the head l2. The plate 3l vhasv an inclined tongue 3B and check spring stop llug l extending from opposite sides thereof.

The tongue 39 in combination with the iront surface of the plate 3i acts, during the operation of threading the sewing machine, to guide a thread between the proximate attened median portions of a pair of dished tension disks l2 and 43. The disks are centrally apertured and thereby fit over the exterior surface of a hollow, cylindrical, reduced-diameter neck trl formed integral with and extending concentrically from the front end of the barel 32. The disk e2 enters a 'countersunk recess de formed in the front of the plate 3l, thus insuring that a thread will always be guided between the disks l2 and 43 and not behind the disk d2. The rear end of the barrel 32, that enters the hole 29, is diametrically slotted as at fil and thereby provides a pair of longitudinal slits for accommodating opposed diametrical lugs 48 formed on the external circumference of an internally threaded and eX- ternally shouldered abutment nut @9. A biasing means, in the form of a coiled compression spring 5S, 'lits into the hollow barrel 32 and biases the -nut i9 in a direction rearwardly of the plate 3l. A hollow cylindrical sleeve 52, having an annular ring iis formed integral therewith and V.an end 54 (Fig. 3) of reduced internal diameter.4

retainer means apairofthread tensioning disks carried cna-frontportion of said support member, and an adjusting means located partly in iront of said disks and'partly within-said support member. j 2. A tension -device for sewing machines comprising a plate, a hollow cylindrical barrel extending frorn said plate rearwardly thereof, a check spring surrounding said barrel, a sleeve adjustably secured to said barrel and having a hole for anchoring -vone end of said check spring, a compression spring positioned within said barrel, a nut slidably mounted within said barrel and biased rearwardly by said compression spring, a neck formed on the'forward endofsaid barrel. a plurality of thread tensioning disks carried by said neck, and a .screw threaded' into v"said'nut and arrangedto presssaid disks together and against said plate.

3. A' tension device for sewing machines comprising a plate, a hollow cylindrical barrel secured vto :said plate and extending rearwardly thereof, a compression spring within said barrel, a threaded nut engaging one end'of saidspring, a pair of tensioning disks positioned in front of said plate, and an adjusting screw having a head in front of said disks and a threaded stem ,adjustably screwed into said nut.

el. A tension device for sewing machines comprising a hollow support member, a biasing means within said support member, a Abias compressing member slidably positioned within said support member, a pair of thread-tensioning carried on said support member and located entirely in iront of said biasing means, ano. an adJusting member located partly in iront or said disks anu partly within said support.

5. A tension device for sewing machines comprising a hollow cylindrical barrel, a compression spring within said barrel, a threaded nut engaging said spring and slidably positioned within said barrel, a pair of tensioning disks carried on the iront end or said barrel, and an adjusting screw having a head in iront I' said disks and a threaded stem screwed into said nut.

6. A tension device Afor sewing machines, comprising, a hollow cylindrical supporting member, opposed tension-disks mounted upon a forward portion of said supporting member, a tensiondisk compressing spring housed in a rearward portion of said supporting member, and means including an adjusting screw extending through said supporting member for varying the tensiondisk compressing force of said spring.

7. A thread-tension device for sewing machines. comprising, a tubular supporting member, a plate rigidly carried by said supporting member intermediate the ends thereof, a pair of opposed ten` sion-disks mounted on said supporting member at one side of said plate, a tension-disk compressing spring housed in said supporting member at the opposite side of said plate, and means including an adjusting screw extending into said supporting member from the tension-disk side of said plate to the compression spring side thereof for changing the effective pressure of said spring.

8. A thread-tension device for sewing machines comprising, a tubular supporting member, a plate rigidly carried by said supporting member intermediate the ends thereof, and a check-spring carried by said supporting member, said spring having one end wrapped around said support at one side of said plate and the other end wrapped around said support at the other side of said plate. s

9. A thread-tension device for sewing machines comprising.' a tubular supporting member, a plate rigidly carried by said supporting member intermediate the-ends thereof, a check spring carried by said support member, said spring having -mediate the ends thereof, a pair of opposed tension-disks mounted on said supporting member at one side of said plate, a tension disk compressing 'spring housed in said supporting member at thev opposite side of said |plate, and a check-spring surrounding said supporting member at the compression spring side of said plate and terminating at oneend in a loop embracing said supporting -memberat thesideof said tension-disks -remote from said plate.

11. A tension device for sewing machines comprising a hollow cylindrical barrel, a check spring surrounding said barrel, a sleeve adjustably secured to said barrel and having a means for anchoring one end of said check spring, a compression spring positioned Within said barrel, a nut slidably mounted though held from turning within said barrel and biased rearwardly by said compression spring, a neck formed on the forward end of said barrel, a plurality of thread tension disks carried by said neck, and a screw threaded into said nut and arranged to press said disks together in a direction toward said barrel.

l2. A tension device for sewing machines comprising a hollow cylindrical barrel, a pair of tensioning disks carried by the front end of said barrel, a disk-biasing compression spring carried in the back end of said barrel, a check spring having a coiled portion which surrounds the back end of said barrel and a loop which surrounds the front end of said barrel, a guard plate positioned in front of said check spring loop, and radially inwardly bent ears on said guard plate, said ears providing clearance for said check spring loop.

13. A tension device for sewing machines comprising a hollow cylindrical barrel, a pair of tension disks carried on the front of said barrel, a disk-biasing compression spring carried on the back end of said barrel, a check spring having a coiled portion which surrounds the back end of said barrel and a loop which surrounds the front end of said barrel, and an anchoring means for one end of the cheek-spring adjustable relative to said hollow cylindrical barrel.

14. A thread-tension device for sewing machines comprising, a hollow support member, a mounting means rigidly secured to said support member between the ends thereof, a pair of tension disks mounted on said support member in front of said mounting means, a guarding means having a plurality of spacing members and at least one forwardly extending member, said guarding means being mounted on said support member in front of said tension disks, an indicating means having a backwardly extending member for engaging said forwardly extending member on said guarding means, a compression spring housed in said support member at the 0p- 7 ps'ite-'side of said m'oimting means from said tension disks, a spring compressing member located iii-said support'. member beh-ind said compression spring, an adjusting screw having a head; forenga'ging Y said indicati-ng means, said .adjusting serewhaving a stem that. enters said. hollow. supportmember and engages said spring compressmember, and separableengaging means -for securing said adjusting screw to vsaid indicating meansferturning movement therewith.

-1-5'. A thread-tension device for sewing ma,- chines, comprising, a tubular support memberr a plate rigidly carried by said supporting. member .intermediatei-ts ends, a pair of opposed tensiondisk's "mounted on said supporting member in front of said plate, a guard plate'having .a..p1u-

"i'aiity'of back-Wardly extending lugs and asingle forwardly extending lug mounted on said supporting member in front of said .tension disks,..a .dial 'Washer having a .backwardly extending lug mdtmted on said supporting member in front of said-guard plate, said `dial washer being provided 'withsa plurality of equally spaced holesin the mee-thereof, a tension ldisk compression -spring Ahcursedv said support. member at the opposite 'side of said plate 'from lsaaid .tension disks, a. Athreaded nut housedv insaid supporting member 'berand is screwed into .said threadedV nut.

LEONARD C. MARSAC.

YREIETERJEJNICES CITED The following references are of record in the frle of this` patent:

UNITED STATES PATENTS Number Date 472,097 Wilcox-.et a1. Apr. 5, 1892 781-,861 Allen Feb. 7, 1905 875,610 Parkes Dec. 31, 1907 1,534,264 Hanson ..Apr,2l, 1925 .1,820,119 Chason Aug. 25, 1931 .1,862,658 .Chason June 14, 19.32

2,131,005 .Chason Sept. 20, 1938 

